Reversible wrist watch

ABSTRACT

The reversible watch includes first ( 1 ) and second ( 2 ) cases mounted back-to-back and each having a back cover and securing elements for securing it to the other case in a way which the user can dismantle. In a particular embodiment, each of the cases includes horns ( 5 ) through which bars ( 8, 9 ) pass. The bars are also used as means for securing the first case to the second and as means for securing each of the ends ( 12, 13 ) of the wristband ( 15 ) to the assembly formed by said first and second cases. In another embodiment, the back covers of the two cases include elements for securing them to each other, and the assembly of the two cases is mounted in a reversible manner on a support secured to a non-reversible wristband.

BACKGROUND OF THE INVENTION

The present invention relates to a reversible wristwatch including afirst case enclosing elements able to control a first display and asecond case enclosing elements able to control a second display, saidfirst and second cases each having a back cover and being placedback-to-back.

Several reversible watches which more or less answer the definitiongiven above have already been proposed.

The watch disclosed in Swiss Patent No. 646 56 is formed of two partssecured to each other and each constituting one of the faces of thereversible watch.

These two parts form a single water-resistant case which is pivotedalong its six o'clock-midday axis on two bars each accommodating one ofthe ends of a wristband. The case includes two lateral covers hinged tothe case at one of their ends, covering the lateral edges of the watchcase in the operating position. In this construction, the respectivemiddle parts of the two parts of the watch are secured to each other bymeans of screws. In general it is to be noted that the proposedconstruction is complicated and requires many constituent parts both forsecuring the middle parts and for attaching the ends of the wristband tothe assembly thereby formed. Should the two parts of the watch requirebatteries to operate, it is difficult to see how access could beobtained to the batteries without unscrewing all the screws connectingthese two parts beforehand, which cannot easily be done by an ordinaryuser. European Patent No. 0 359 181 discloses a watch having a case withtwo displays arranged on opposite faces, this case being mounted by ahinge on a base plate secured to the wristband. This enables the case tobe raised to read the display placed on the back, but the watch canobviously not be worn in this position during other activities, since itwould quickly be damaged. U.S. Pat. No. 5,479,381 discloses a reversiblewatch having at least two opposite faces and at least one movement. Themiddle part is secured to an extending wristband by means of horns sothat the wearer of the watch can pass from one face to the other withouthaving to take the watch off his wrist. However the description relieson movements mounted in a single case and there is thus no reason tofind a solution for attaching two distinct cases, which are themselvessecured to a wristband.

Swiss Patent No. 680 329 also shows a reversible timepiece of the typeindicated above in the preamble. This article includes a central portionon each side of which is mounted a complete watch with its dial directedoutwards. Each watch is hinged on this central portion, this latterhaving horns for attaching a wristband. It is clear that thisarrangement leads to a watch of significant thickness, given thepresence of the central portion.

A reversible watch by the name of“Reverso” (registered trademark) isalso known, made of a single case engaged on a cradle-shaped supportprovided with slide-ways, the support being in turn secured to thewristband. The proposed construction leads to a rather thick watch whichis generally only provided with a mechanical movement, since the use ofan electric movement would require, to replace the battery, eitheropening the case, or a lateral battery hatch if both sides of the watchwere each fitted with a display. A watch of this type is disclosed, inits simplest embodiment, in French Patent No. 712 868.

SUMMARY OF THE INVENTION

It thus appears that the state of the art in field of reversiblewristwatches proposes on the one hand watches with a single case, and onthe other hand watches with two cases. The first category has thedrawback of a generally high cost, because of the special constructionof the double face case and, as appropriate, movements with double facedisplays, as well as difficulties concerning battery replacement in thecase of electric movements. The second category, illustrated by SwissPatent No. 680 329, has in particular the drawback that the assembly isof considerable thickness and the mounting of the cases on a commonsupport is complicated.

The present invention concerns a watch in the second category andproposes creating a watch of moderate thickness which can be bothmanufactured at moderate cost and be very comfortable to use. Moreover,in the case of watches including electric batteries, this means creatinga construction which allows easy replacement of the battery by the user,without the aesthetic appearance of the watch and the manufacturing costbeing particularly affected.

The invention therefore concerns a reversible wristwatch of the typeindicated in the preamble, characterised in that each of the two casesincludes at least one securing element arranged to be attached in aremovable manner to a corresponding securing element of the other case,to secure the cases to each other in a position in which theirrespective back covers are adjacent.

Any intermediate element such as a support arranged between the twocases, can thus be omitted, which substantially reduces the thickness ofthe assembly and simplifies the final assembly. Each of the two casesmay advantageously be individually sealed and be designed from a commontype of mono-face watch case, to which one need only add the elementsfor securing it to the other case. These securing elements may beconcealed in the region of the back cover of the cases or may be madeclose to the edges of the cases in a barely visible or invisible form.Moreover, if one of each of the cases has to contain an electric batterythe back cover of the case in question may includes an ordinary batteryhatch, which will be concealed by the other case but will remain easilyaccessible to the user because the latter may easily separate the casesby dismantling their mutual securing means. Battery replacement willthen be performed as in an ordinary watch.

In a particular embodiment, the securing elements of each of the casesinclude horns through which bars pass, these bars acting both as meansfor securing the first case to the second and as means for securing eachof the ends of the wristband to the assembly formed by said first andsecond cases.

Otherwise the securing elements may be arranged on the back cover of thecase, for example in the form of sliding assembly elements of thedovetail type.

In another particular embodiment, the two cases secured to each otherform a movable case, which is mounted so as to pivot and slide on asupport attached to a wristband, the support having two parallel lateralbars between which the movable case is placed in two mutually oppositeuse positions, positions in which two opposite lateral faces of themovable case extend along said bars. An advantageous arrangement in thiscase is for each support bar to be provided with an articulationtrunnion, which is engaged in a slide-way of the corresponding lateralface of the movable case, and in that said slide-way is formed byjuxtaposing two recesses of L-shaped profile, each arranged along anedge of the back cover of each case. Each trunnion may be secured to aremovable part held by means of a wristband attachment bar, so that theuser can easily remove the movable case from the support to separate thetwo cases, for example to change one of them or to replace a battery.

Other features and advantages of the present invention will appear fromthe following description, made with reference to the annexed drawingsand presenting by way of explanatory but non-limiting example, variousadvantageous embodiments of the invention, wherein, in such drawings:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a blown up perspective view of the various elements forming afirst embodiment of a reversible watch according to the invention,

FIG. 2 is a blown up perspective view of the various elements forming asecond embodiment of a reversible watch according to the invention,

FIG. 3 shows the second embodiment shown in FIG. 2 at a different angle,

FIG. 4 shows a perspective view of a third embodiment of a reversiblewatch according to the invention, in five successive positions of amovable case formed of two cases arranged back-to-back,

FIG. 5 shows a perspective view of the two cases of the watch of FIG. 4,

FIG. 6 is a blown up perspective view of the watch of FIG. 4, and

FIG. 7 is a lateral view of the movable case, along the arrow VII ofFIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

As FIGS. 1 to 3 show, the reversible wristwatch has a first case 1enclosing elements (not shown) able to control a first display 3 and asecond case 2 also enclosing elements (not shown) able to control asecond display (not shown as located under case 2). These first andsecond cases are placed back-to-back so as to cause the displays toappear on either side of the assembly thereby formed. Display 3 shownhere is an analogue display but could be of any other form, for exampledigital. The display not shown and affecting case 2 may be eitherdigital or analogue. It will also be noted that cases 1 and 2 maydisplay the time, for example the local time for the first and that ofanother time zone for the second. One could however, display somethingother than the time, for example an interval of time (chronographfunction) or a message (pager function). It will thus be understood thatvarious combinations are possible.

The reversible wristwatch according to FIGS. 1 to 3 is characterised inthat each of cases 1 and 2 includes securing elements in the form ofhorns, referenced in the first embodiment of FIG. 1 and referenced 5 inthe second embodiment of FIGS. 2 and 3, removable bars 6 and 7 passingthrough these horns in the first embodiment and removable bars 8 and 9in the second embodiment. As will be noted in these Figures, these barsfulfill a dual function: on the one hand they act as means for securingfirst case 1 to second case 2 and, on the other hand, as means forsecuring each of the ends of the wristband to the assembly formed by thefirst and second cases. Thus ends 10 and 11 of wristband 14 of the firstembodiment (FIG. 1) are secured to the assembly formed by cases 1 and 2by bars 6 and 7 respectively. Likewise, ends 12 and 13 of wristband 15of the second embodiment (FIGS. 2 and 3) are secured to the assemblyformed by cases 1 and 2 by bars 9 and 8 respectively.

In summary, two bars only are sufficient both to secure the two cases toeach other in a removable manner and to secure the ends of the wristbandto the assembly thereby formed. To the Applicant's knowledge, such anarrangement has never been proposed, such arrangement considerablysimplifying the assembly of the watch both as regards the time whichsuch assembly takes and the number of parts to be implemented.

Two embodiments of the invention which put into practice theaforementioned principles will now be examined in detail.

The first embodiment is illustrated in FIG. 1. The reversible watchincludes a first case 1 with its display 3 and a time-setting controlcrown 80 and a second case 2 whose display is not apparent, this secondcase having its own time-setting control crown 81. The two cases 1 and 2are arranged back-to-back, so that their respective back covers 85 and86 are adjacent. First case 1 includes, at six o'clock, a pair of horns16 and 17 and, at twelve o'clock, another pair of horns 20 and 21.Second case 2 includes, at six o'clock, a pair of horns 18 and 19 and,at twelve o'clock, another pair of horns 22 and 23. Each of these hornsis provided with a hole respectively referenced 24, 25, 28, 29, 26, 27,30 and 31. The diameter of each hole is adjusted to the diameter of bars6 and 7. Each horn of first case 1 is juxtaposed with a correspondinghorn of second case 2. Thus, horn 16 is located next to horn 18, horn 17next to horn 19, horn 20 (not shown) next to horn 22 and horn 21 next tohorn 23. When the corresponding horns are juxtaposed, i.e. when cases 1and 2 are placed back-to-back, a recess 32 is created at six o'clockwhich is occupied by end 11 of wristband 14, and a recess 33 is createdat twelve o'clock which is occupied by end 10 of wristband 14. Ends 11and 10 of wristband 14 are provided with a hole referenced respectively34 and 35. These holes 34 and 35 are arranged in alignment with the holeof horns to accommodate bars 7 and 6 which are inserted by slidingthrough the horns, so that, once inserted, these bars secure the firstcase to the second and wristband 14 onto the assembly thereby formed.

In the embodiment shown in FIG. 1, it can be seen that case 1 may alsobe mounted on case 2 by rotating it through 180° in its plane. Thiswould then produce an incorrect mounting unsuited to a reversiblewristwatch. This takes account of the symmetrical arrangement of thehorns of first case 1 with respect to the horns of second case 2. Inorder to avoid this, the symmetry can be broken for example by movinghorns 16 and 17 of case 1 towards the exterior of said case 1 and horns18 and 19 of case 2 towards the inside of said case. At that moment,case 1 can only be mounted in a single direction on case 2.

The second embodiment is illustrated in FIGS. 2 and 3. In thisembodiment, the first and second cases 1 and 2 include, at six o'clockand at twelve o'clock, four horns 5, each horn of the first case beingsuperposed on and encased in a horn of the second case when the casesare placed back-to-back. At that moment, three recesses are created atsix o'clock and twelve o'clock, namely recesses 36, 37 and 38 at sixo'clock and recesses 39,40 and 41 at twelve o'clock. Recesses 36, 37 and38 are 30 occupied by end 13 of wristband 15, this end being dividedinto three sections 42, 43 and 44. Recesses 39, 40 and 41 are occupiedby end 12 of wristband 15, this end being divided into three sections45, 46 and 47.

First case 1 has, at six o'clock and in order, a first male horn 48provided with a hole 49 and encased in a first female horn 50 of secondcase 2, second 51 and third 52 female horns respectively encased insecond 53 and third 54 male horns of second case 2, the male horns eachbeing fitted with a hole respectively referenced 55 and 56, and a fourthmale horn 57 provided with a hole 58 and encased in a fourth female horn59 of second case 2. First case 1 has, at twelve o'clock and in order, afirst female horn 60 encased on a first male horn 61 of second case 2,this horn 61 being provided with a hole 62, second 63 and third 64 malehorns each provided with a hole respectively referenced 65 and 66 andrespectively encased in second 67 and third 68 female horns of secondcase 2, and a fourth female horn 69 encased in a fourth male horn 70 ofsecond case 2, this horn 70 being provided with a hole 71. The threesections 42, 43 and 44 of end 13 of wristband 15 are provided with ahole respectively referenced 72, 73 and 74 and the three sections 45, 46and 47 of end 12 of wristband are provided with a hole respectivelyreferenced 75, 76 and 77. These holes are arranged in alignment with theholes of the horns to accommodate removable bars 8 and 9 which securefirst case 1 to second case 2 and wristband 15 to the assembly therebyformed.

In the embodiment shown in FIGS. 2 and 3, it can be seen that case 1 canonly be mounted one way on case 2 and that it is therefore not possibleto rotate it by 180° in its plane then to mount it on case 1. This isdue to the configuration and alternating male and female horns. Indeed,if case 1 is rotated in the wrong direction, male horns 63 and 64 ofcase 1 will meet other male horns, in this case male horns 53 and 54 ofcase 2.

The embodiment shown in FIG. 2 shows, in back cover 86 of case 2, acover 82 closing a battery hatch 83. Since this cover can exceed thelevel of the back of case 2, a recess in portion 84 is provided In backcover 85 of case 1, as shown in FIGS. 2 and 3, this recess in portionbeing Intended to accommodate a battery hatch cover which is not visibleand which Is located in the back cover of case 1.

It will also be noted that the embodiment shown in FIGS. 2 and 3 usesthe construction of the Swatch (registered trademark) watch wherein theends of the wristband each include three sections and the case two timesfour horns.

It will be noted finally that the present invention offers an extremelythin reversible watch especially if two cases of small thickness areselected, such as, for example, those marketed under the name SwatchSkin (registered trademark).

The way in which wristband 14 or 15 is manufactured is not describedhere. It may be an extending wristband as disclosed in U.S. Pat. No.5,479,381 or a leather strap provided with a pivoting buckle, asdisclosed in German Patent No. 35 12 369.

In the event that first and second cases 1 and 2 are fitted with powersupply batteries, it can be seen that the arrangement proposed by theinvention allows the batteries to be changed easily. One need only takeout the bars to separate the cases and have access to the batteryhatches. The horns on one side of the watch may further be arranged toform a hinge, so that one need only take out the bar from the other sideto separate the cases and have access to each battery hatch.

In the embodiment shown in FIGS. 4 to 7, the reversible wristwatchincludes a reversible movable case 100 formed by assembling a first case101, enclosing a first clockwork movement provided with a first display103, for example of the analogue type, and a second case 102 enclosing asecond clockwork movement provided with a second display 104, forexample of the digital type. Cases 101 and 102 have a generally squareor rectangular shape and are arranged back-to-back, so that theirdisplays 103 and 104 appear respectively on the two opposite faces ofmovable case 100. As in the preceding example, the two displays may bearranged to display the time, but one or the other could displaysomething else, for example a measured time, an alarm time, stored data,a message received via radio or other alphanumerical data, orcombinations of such elements.

Movable case 100 is mounted so as to pivot and slide on a rigid support105 secured to the two ends 106 and 107 of a wristband 108 which may ormay not be reversible. This support is shown in detail in FIG. 6 andincludes two parallel bars 110 connected by a bottom plate 112, so thatsupport 105 has a cradle shape longitudinally the inside of which isoccupied by movable case 100. Each bar 110 includes horns 113 providedwith holes 114 for attachment to wristband 108 in the same way as in thepreceding example, i.e. by means of two removable bars 115 which alsopass through holes 109 of ends 106 and 107 of the wristband.

Each bar 110 includes a through hole 116 opening out into an innervertical face 117 of the bar, facing the opposite bar 110. Each hole 116is intended for the passage of a cylindrical trunnion 118 secured to aremovable part 119 which is housed in a recess 120 of bar 110, whiletrunnion 118 engaged through hole 116 emerges from face 117 of the barto form an articulation pivot. Each part 119 has the same external shapeas horns 113 and, like the latter, it includes a hole 121 intended forthe passage of bar 115, so that this bar holds part 119 In position inbar 110 as is seen in FIG. 4(e). It will also be noted that inner plate112 of support 105 does not extend over the entire length of bars 110,but has an edge 122 set back from a vertical line passing through holes116, in order to release the space below trunnions 118 for a reasonwhich will appear hereinafter.

In FIG. 5, the two cases 101 and 102 are shown so that their respectiveback covers 125 and 126 are visible, provided with battery hatches 127and 128 to allow easy replacement of the battery powering the clockworkmovement. A control crown 129 is provided on case 101, as is a controlcrown 130 on case 102, in the usual position. On its side opposite thecrown, each case has a small recess 131, 132, which, when the cases areassembled as is seen in FIG. 4, allows the user to insert a nail underthe crown to pull it. Along the two other edges opposite the back coverof first case 101, there are two longitudinal recesses 133 having anL-shaped profile and extending symmetrically over most of the length ofthe side of the case. Two similar longitudinal recesses 134 are arrangedalong two opposite edges of back cover 126 of second case 102. Further,a wide groove 135 having a dovetail profile passes right through backcover 125 of first case 101 in its central zone. Likewise, in itscentral zone, back cover 126 of second case 102 has a wide rib 136having a dovetail profile which corresponds to that of groove 135 inorder to be encased therein by sliding In it when the cases are putback-to-back, in the position shown in FIG. 6. Thus, groove 135 and rib136 constitute elements for directly securing one case to anotherwithout inserting any intermediate element.

When the two cases 101 and 102 are thus assembled, as is seen in FIG. 7,their respective longitudinal recesses 133 and 134, which are juxtaposedalong each side of movable case 100, together form a longitudinalslide-way 140 In each lateral face 141 of the movable case, thisslide-way having closed ends 142 and 143. When movable case 100 isplaced between the two bars 110 of support 105, the two mutuallyopposite trunnions 118 are each engaged in one of slide-ways 140 ofmovable case 100, so that the latter can pivot and slide on thetrunnions, while the two cases are held laterally by faces 117 of bars110. Sliding is stopped by one or other of ends 142 and 143 of theslide-ways.

When the movable cases is placed flat in support 105 in one of the twopositions (a) and (e) shown in FIG. 4, it is prevented from pivoting andsliding by two opposite clicks 144 which emerge from faces 117 of thebars engaging in slide-way 140. A click of this type may be formed by apin with a spherical head mounted on a spring.

FIG. 4 shows five successive positions (a) to (e) of movable case 100when a user turns it. Position (a) is a first use position wherein firstcase 101 presents its analogue display 103. By lifting up the left edge145 of the case, the holding of clicks 144 is overcome and the case isset in inclined position (b) by pivoting on trunnions 118. The rightedge 146 of the case is then lowered between bars 110 of support 105, inthe zone into which central plate 112 does not extend. In order to passto position (c), the case is pulled backwards so that it slides on thetrunnions to the corresponding end of slide-way 140. Edge 146 of thecase is then higher than plate 112. Case 100 is then pivoted to thehorizontal position (d) then it is made to slide horizontally to theleft above plate 112 to bring it to the second use position (e) whereincase 102 is at the top and presents its digital display 104. Clicks 144are then again engaged in slide-way 140 to stabilise movable case 100.

The same operations are repeated to pass from position (e) to position(a).

The construction described above allows the batteries contained in cases101 and 102 to be replaced easily, both by an average user and by awatchmaker. The two cases can be separated as shown in FIG. 6, byremoving the two bars 115, then the two parts 119 to separate movablecase 100 from support 105, then the two cases are separated by slidingthe dovetail assembly. The two battery hatches 127 and 128 then becomeaccessible as in an ordinary watch. Next, the watch is reassembled bythe reverse operations.

It will be noted that in the example shown in FIGS. 4 to 7, trunnions118 are not in proximity to one end of bars 110 of the support, becauseremovable parts 119 which carry them cannot transmit force between thewristband and the support and would not be properly guided to the end ofthe bar. One may however design variants wherein trunnions 118 aresituated very close to the end of the bar in order to abut against oneend of slide-way 140 in the two use positions of the case. For example,each trunnion could be provided at the end of a screw passing throughthe bar.

It will be noted that the watch shown in FIGS. 4 to 7 could also includestop members to prevent the movable case moving to the left beyondpositions (a) and (e) of FIG. 4. For example, ends 142 and 143 ofslide-way 140 could be deepened or widened locally so that clicks 144engage more deeply therein. Another solution consists in providing atleast one stop projecting at the left end of each face 117 of bars 110,to act as a stop for the movable case. A stop of this type may also beformed by an element connecting the left ends of the two bars to form arigid U-shaped frame. Plate 112 could then be omitted.

Instead of sliding the movable case on the support in a perpendiculardirection to the wristband, with pivoting about an axis parallel to thegeneral direction of the wristband, one can provide the oppositearrangement, i.e. sliding the case in a direction parallel to thewristband, without departing from the scope of the invention. In suchcase, horns 113 of support 105 could be replaced by horns arranged inthe extension of bars 110, or by two handles connecting the ends of thetwo bars and each attached to one end of the wristband, the support thenhaving the form of a rectangular frame. These handles may also beprovided with several similar horns to horns 113 shown in FIGS. 4 and 6.

What is claimed is:
 1. A reversible wristwatch including a first caseenclosing first elements able to control a first display and a secondcase enclosing second elements able to control a second display, saidfirst and second cases each having a back cover and being placedback-to-back, wherein each of said first and second cases includes atleast one securing element arranged to be secured in a removable mannerto a corresponding securing element of the other of said first andsecond cases, to secure the first and second cases to each other in aposition in which their respective back covers are adjacent, wherein thesecuring elements of each of the first and second cases include hornsthrough which bars pass, said bars acting both as means for securing thefirst case to the second case and means for securing opposite ends ofthe wristband to an assembly formed by said first and second cases, andwherein the first and second cases include at six o'clock and twelveo'clock four horns, each horn of the first case being superposed on andencased in a horn of the second case when said cases are placedback-to-back to define at six o'clock and twelve o'clock three recesseswhich are occupied by the corresponding end of the wristband dividedinto three sections, the first case having at six o'clock and in order,a first male horn provided with a hole and encased in a first femalehorn of the second case, second and third female horns respectivelyencased in second and third male horns of the second case which are eachprovided with a hole; and a fourth male horn provided with a hole andencased in a fourth female horn of the second case, said first casehaving, at twelve o'clock and in order, a first female horn encased on afirst male horn of the second case, said first male horn being providedwith a hole, second and third male horns each provided with a hole andrespectively encased in second and third female horns of the secondcase, and a fourth female horn encased in a fourth male horn of thesecond case, said fourth male horn being provided with a hole, each ofthe three sections of the ends of the wristband being provided with ahole arranged in alignment with the holes of the horns to accommodatethe bars which secure the first case to the second case and thewristband to the assemble thereby formed.
 2. The wristwatch of claim 1,wherein each case contains an electric battery and includes a batteryhatch provided with a removable cover in its back cover.
 3. A reversiblewristwatch including a first case enclosing first elements able tocontrol a first display and a second case enclosing second elements ableto control a second display, said first and second cases each having aback cover and being placed back-to-back, wherein each of said first andsecond cases includes at least one securing element arranged to besecured in a removable manner to a corresponding securing element of theother of said first and second cases, to secure the first and secondcases to each other in a position in which their respective back coversare adjacent, and wherein the first and second cases secured to eachother form a movable case, which is mounted so as to pivot and slide ona support secured to a wristband, the support having two parallellateral bars connected to each other, between which the movable caseoccupies two mutually reversed use positions, in which two oppositelateral faces of the movable case extend along said bars.
 4. Thewristwatch of claim 3, wherein each lateral bar of the support isprovided with an articulation trunnion which is engaged in a slide-wayof the corresponding lateral face of the movable case, and wherein saidslide-way is formed by juxtaposing two recesses of L-shaped profile,each arranged along an edge of the back cover of each case.
 5. Thewristwatch of claim 4, wherein each lateral bar of the support isprovided with securing means including a removable bar for securing itto the wristband and wherein said trunnion is secured to a removablepart which is held in place on the bar by means of the removable bar. 6.The wristwatch of claim 3, wherein the movable cased slides along thesupport in a perpendicular direction to the wristband.
 7. The wristwatchof claim 3, wherein the movable case slides on the support in a paralleldirection to the wristband.
 8. The wristwatch of claim 3, wherein eachcase contains an electric battery and includes a battery hatch providedwith a removable cover in its back cover.
 9. A reversible wristwatchincluding a first case enclosing first elements able to control a firstdisplay and a second case enclosing second elements able to control asecond display, said first and second cases being individually sealedand each having a back cover and being placed back-to-back, wherein eachof said first and second cases includes at least one securing elementarranged to be secured in a removable manner to a corresponding securingelement of the other of said first and second cases, to secure the firstand second cases to each other in a position in which their respectiveback covers are adjacent, and wherein said securing elements arearranged on the back cover of each of said first and second cases. 10.The wristwatch of claim 9, wherein the securing elements includeassembly elements of the dovetail type.
 11. The wristwatch of claim 9,wherein the first and second cases secured to each other form a movablecase, which is mounted so as to pivot and slide on a support secured toa wristband, the support having two parallel lateral bars connected toeach other, between which the movable case occupies two mutuallyreversed use positions in which two opposite lateral faces of themovable case extend along said bars.
 12. The wristwatch of claim 11,wherein each lateral bar of the support is provided with an articulationtrunnion which is engaged in a slide-way of the corresponding lateralface of the movable case, and wherein said slide-way is formed byjuxtaposing two recesses of L-shaped profile, each arranged along anedge of the back cover of each case.
 13. The wristwatch of claim 12,wherein each lateral bar of the support is provided with securing meansincluding a removable bar for securing it to the wristband and whereinsaid trunnion is secured to a removable part which is held in place onthe bar by means of the removable bar.
 14. The wristwatch of claim 11,wherein the movable case slides along the support in a perpendiculardirection to the wristband.
 15. The wristwatch of claim 11, wherein themovable case slides on the support in a parallel direction to thewristband.
 16. The wristwatch of claim 9, wherein each case contains anelectric battery and includes a battery hatch provided with a removablecover in its back cover.